A Certain Transcendent Sense of Familiarity
by CockADoodleDoNot
Summary: In the aftermath of Academy City's latest hit calamity, Accelerator struggles through an enigmatic ailment and the deific ambitions of a sinister organization. Kamijou attempts to help him through it while struggling through his own disorientation. Elsewhere and elsewhen, a black-haired boy drags a white-haired boy out of the shadows and promises to be his family.


tbh I haven't done any creative writing in years and it probably shows lmao

prays to kamachi for forgiveness for the next-level butchering i'm about to do to his characters

Aren't disclaimers sorta implicit in the word "fanfiction"? Well, whatever the case, **Toaru Majutsu no Index and its characters is intellectual property of Kamachi Kazuma and not me.**

* * *

**Part 1**

"We're...we're back,"

Under the watchful gaze of the eventide full moon, a certain highly-acclaimed hospital in School District 7 was greeted by a figure adorned in white with an unconscious figure in black hauled over his shoulder. Between heavy gasps, the white figure had announced their triumphant return to no one in particular.

The frog-faced doctor, embellished by the aptronym Heaven Canceller, half-jokingly welcomed them back, for they were no strangers to the hospital among the twenty-three districts of Academy City.

Academy City.

Located in a segment of Western Tokyo, resident to 2.3 million, eighty percent of which or students, boasted of technology thirty years ahead of the world, with a prolific esper development program to boot.

And within this city, the existences of two particular figures are intertwined deep into its very foundation laid down by Board Chairman and General Superintendent Aleister Crowley, decades before they had even been born. Both first opened their eyes to the world in midwinter of sixteen years ago, were 168 cm in height, and were avid fans of Sunatory BOZU No Sugar Black Coffee.

Kamijou Touma and the #1.

Imagine Breaker and Accelerator.

The One who Purifies God and Slays Demons and The One who Wields the Power of God.

最弱と最強.

The recent calamity had contributed to their nearly full capacity, but hospital had accepted them nonetheless.

And in the midst of the chaos of the hospital night, yet blissfully unaware of it, a certain spiky black-haired boy had a dream. Like the smell of an old home left vacant for years, or the lingering taste of an old childhood favorite dish, or the sound of a long bygone melody, that dream left a warm, nostalgic yet melancholic feeling of familiarity within his chest.

He dreamt of an silky white-haired boy that gave the impression of a mirror. All animosity and hostility directed towards the boy would be reflected back towards the very people who directed it. But they didn't like that. Those who barred their pride, jealousy, or fear, would have their own depravity displayed right back. Unable to confront their own faults and inner ugliness, they rejected their darkness and attributed it all to the boy, branding him a monster and shrouding him in darkness until darkness was all the boy saw.

Nevertheless, on the off chance that some light was shone towards the mirror, maybe light would shine right back. When And perhaps, when a smile was directed at it, a smile would be reflected back as well.

The spiky black-haired boy by the name of Kamijou Touma decided he wanted to protect the smile of that boy and that of others to come, no matter what the dangers and what the cost.

* * *

**Part 2**

"This is somewhat uncharacteristic of you."

"…Huh?" the white-haired monster known as Accelerator, controller of any and all vectors, slowly looked up across the patient he and the frog-faced doctor had been operating on.

"You don't typically go out of your way to actively and accommodatingly aid people whose issues don't concern you or your familiars."

"My battery dying typically isn't a non-issue either," he retorted.

"You didn't even click your tongue when you offered your help."

"…"

"...Could it be that he's rubbing off on you?"

Accelerator clicked his tongue in annoyance, but didn't answer Heaven Canceller's question.

"I also get something out of this, so it's more like killing two birds with one stone," he refuted.

"How so?"

"That's none of your concern."

The frog-faced doctor's knit eyebrows clarified that he had no intention of obeying. Accelerator gave an exasperated sigh and drew the subject back to the objective at hand.

"I've stabilized the vitals, but located a number of irregularities. It seems to be the natural reaction rejection espers have to magic, but the specs are different"

With that minor digression among a sea of cardiac monitors beeps and hospital staff rustling about, the two diligently worked together throughout the night.

* * *

Heaven Canceller observed as Accelerator reviewed a patient's case file. His red eyes skimmed through the paper, but frowned. He retried, skimming through two or three more times, each time slower than the last. His usual razor-sharp focus seemed to have dulled considerably.

"You should get some rest."

"I can hold out."

"That doesn't mean you should," the doctor reprimanded. "Besides, you look dead on your feet."

"..."

"And judging by your glazed, unfocused eyes, flushed cheeks, signs of lethargy and fatigue, slight confusion, minor chills, mild sensitivity to light, and delayed reaction time, it would appear that you're running quite the fever as well," continuing the doctor, thorough as usual in his analysis.

"…!"

"I had saliva samples from your surgical mask sent to be analyzed earlier, and the cause doesn't seem to be pathogenic, at least not for the standard airborne ailments. It could very well be psychogenic. They don't typically get as severe as what seems to be your case, but knowing that strange brain of yours, it wouldn't be a stretch."

"…Aren't you a bit too thorough?" mumbled the #1, clearly uncomfortable under such careful scrutiny.

"You're one of my patients too," reminded the frog-faced doctor.

He'd suspected something was off the moment he had seen the #1. The hospital had been short on personnel and equipment, so Accelerator had been quick to offer his aid after securing Kamijou.

To the Heaven Canceller, what was odd wasn't that he'd offered his aid. What was odd was that he had done so immediately, not even giving off his usual uncaring façade with so much as a reluctant grumble or irritated complaint. Since they had been short on hands and many patients were in critical condition, Heaven Canceller had not refused the #1's offer. But true to his Hippocratic Oath, the frog-faced doctor had not turned a blind eye and had been examining the #1 as they had worked together throughout the night.

"At least let me get you checked out."

"Not necessary," dismissed Accelerator.

"You won't be doing anyone any favors by straining yourself so hard."

"I won't be doing anyone any favors by letting myself ease up either."

"How so?"

Red eyes widened and as Accelerator realized his slip-up, which did not go unnoticed by the frog-faced doctor's meticulous analysis.

"What'll happen if you let yourself relax?" reiterated the doctor as the #1 averted his gaze.

"Don't you have other patients to attend to?"

"All the emergency and immediate intensive care patients have been treated thanks to your help, and the other doctors and nurses can look after the others. This is actually my break time. I have no other patients to attend to at this time. Well, none other than you."

Accelerator clicked his tongue, but the doctor prodded on undeterred, boring into the #1's stubborn wall.

Eventually, no longer able to avoid the doctor's inquisition or ignore his pounding headache, the #1 sighed and relented.

"Something's wrong…really wrong," he confessed massaging his right temple.

"For you to be admitting something's wrong is worrying in itself."

"I pulled something back at the labyrinth, and something…came over me. I'd managed to keep it at bay by focusing on his safety and stability, but now that the threat is over, I can only hold it back for so much longer."

"What exactly is it?"

"I don't know, but it's volatile and unpredictable. It either relies solely on unconscious calculations or is caused by an outside source, so I can't control it. There's a psychological component to it; it feels like something's trying to get through, something dissipative and dangerous. I'm unstable and a hazard to those around me under its effect. I can't account for it or take that risk. If I stop focusing my power on accomplishing a task and let myself relax, I'm not sure what could happen."

"…Then what did you do?"

Red eyes squinted as his grip on his head tightened.

"…I…don't know," he admitted.

"By the time I'd reached him, his heart had already stopped and he wasn't breathing. his body had been ravaged with natural and supernatural wounds and afflictions alike. His corpse was completely mutilated...it seemed as though he'd already been dead for probably hours. I'm no stranger to death, guts, and gore, but seeing that…"

He trailed off. With an uncharacteristic quiver to his voice and breathing that grew progressively more uneven, he continued.

"Fuck, I admit it…I-I couldn't accept that. It felt like the world was gonna unravel. Nothing felt real. like an old nightmare lost to the void. I'd…never considered or wanted to consider the possibility that he could actually…"

Accelerator broke off for a bit to regain his composure. He took a deep breath and continued.

"…S-So I refused. What happened next was a blur, but when I came to, he had life. Was barely clinging onto it, and an inch away from death, but that was good enough. I tended to his afflictions, seized hold of his body operations, and stabilized him."

While he was no stranger to trauma, recollecting that experience seemed to have taken everything out of the already weary #1, so the frog-faced doctor gave him a moment to rest, which, as his patient had predicted, ended up proving potentially disastrous.

In an instant, Accelerator was flung straight into the frog-faced doctor's desk across the room at faster than lightning speed. He undoubtedly would have crushed it under sheer momentum, but managed to lessen the magnitude upon impact. He then seized up, disappeared for a moment, and emitted a blinding flash. The very air of the room seemed to grow unstable with the boy at the center of the commotion, but the monster managed to recompose himself.

Fortunately, no real damage was done, but he seemed even more worn down than before. He forced himself to conscious attentiveness by manipulating the vectors in his adrenal glands and between synapses in his brain, somewhat mimicking the effects of a natural stimulant, but it seemed as though there was something even he couldn't account for.

As he gasped for breath and struggled on all fours, the frog-faced doctor noticed how his reflection was off by observing a pen that rolled off the disturbed desk and onto the #1's back. Seizing the opportunity, he parted the boy's shoulder-length white hair and laid the back of his hand against the nape of his neck, just below the battery-powered choker-electrode that he himself had designed. It wasn't the best place to check for a fever, but the heat radiating off the #1 would have been worrisome regardless of where it was measured from.

"As I'd thought. You're burning up."

"…gah…h-ahh…" panted the #1 as if affirming the doctor's analysis.

"Your ability may be more or less unparalleled in both strength and versatility, but you're still human," he said as the #1 scoffed between ragged breaths. HC ignored him and continued. "You may be able to supplement many human limits with your ability, but you can't hinder it forever."

"...I...I know."

HC waited for the boy to catch his breath before inquiring.

"Then what are you going to do?"

Accelerator took a deep breath, gathering his strength in one rushed statement.

"Make sure no one gets hurt by whatever the fuck this indisposition is. This hospital still has a Calculate Fortress Containment Ward for analyzing quarantined patients, right? Just throw me in one of those. It has defenses are on par with the Windowless Building and it's equipped with means to bypass my ability."

"It's unlike you to propose to lock yourself up. Especially in one of those. You realize that one of those 'means' involves replacing all oxygen with an incapacitating agent, meant to force you to choose between suffocating yourself in your vector shield or getting knocked out, right? It isn't exactly what I'd call humane."

Accelerator nodded but remained silent, catching his breath again. It appeared that he was barely holding onto consciousness. The frog-faced doctor sighed and further played the devil's advocate.

"It's not good enough. There's no guarantee Calculate Fortress can contain whatever's afflicting you, as its origins and implications are unknown. Calculate Fortress also only works on physical attacks, and you could probably bypass it with your newfound knowledge on magical essence. On top of that, throwing you in there would only serve to worsen your condition, prolong your suffering, and delay the inevitable. To top it all off Last Order, Yoshikawa, Yomikawa, and Qliphah Puzzle 545 certainly wouldn't be pleased with that solution, though I can't say for certain about Worst.

"...Weren't you...the one who told me...to focus on a single goal...?"

"I did. And I still am. Protecting others, addressing the concerns of your loved ones, and allowing yourself to get the help you need don't necessarily have to be separate objectives."

"Then what…do you suggest I…do…?"

"I have an idea."

"…?"

"If you truly want to do what's best for those close to you, sometimes the right thing to do is to just stay by their side, let down your walls, and rely on someone else for once."

"…"

"You can start now by easing yourself into my hands"

Accelerator, barely able to keep his eyes open and seemingly on the verge of passing out, still managed an unconvinced glare. Heaven Canceller sighed and addressed his concerns.

"Don't worry about me," he reassured as he grabbed something off his desk drawer and displayed it. "I have anti-esper equipment specifically designed for situations like these."

"…Will they…no…calculations…?"

"I also have other means of protecting myself from supernatural phenomena. Just give it up and rest."

Unable to keep his eyelids open any longer, Accelerator finally gave in as the world spun around him and his consciousness sizzled out.

* * *

**Part 3**

"Welcome back."

Kamijou rose into consciousness, greeted by the sensation of having been hit by a bus several times over and the vague impression that he had been disassembled and put back together, though at this point it was a sensation he had become accustomed to.

"...What happened this time?"

Opening his eyes, he took note of his surroundings. He had been in this hospital room so many times within the past few months that he might as well call it a second home. He raised his arm to observe the IV imbedded within it. It had sedative properties, so he would probably be sinking back into unconsciousness soon.

"The labyrinth...what happened to it? How is everyone who-"

"They're fine."

Kamijou breathed a sigh of relief and eased up.

"Well, nearly everyone is." backtracked Heaven Canceller. When he saw Kamijou tense up again, attempt to prop himself up only to wince, the frog-faced doctor shook his head.

"Always thinking of others before yourself, eh? It would make my day for you and him both to just ask 'What about me,' for once.

"...Fine. 'What about me?'"

"…Out of all the times you've been battered up and ended up as my patient, this might just be the worst case yet."

"You aren't selling my other feats short by calling this the worst, are you?"

The frog-faced doctor chuckled, but remained serious all the same.

"It's a relief that you're feeling well enough to joke around, but don't take this situation too lightly. It seems as though by the time someone had finally gotten to you, you'd already kicked the bucket."

"…What?"

"Whoever took you out truly took extra precautions and went through every measure to ensure there was a zero percent chance of survival."

"But I'm still alive, relatively unscathed, and I don't think they would have IV drips in the afterlife. You said you can't bring people back from the dead, so how am I still here?"

"You were saved by someone who defied fatality. Someone who refused to accept the conclusion that nothing could be done, who bore the burden of your existence upon themselves and achieved a miracle."

"Who…?"

"You'll see soon enough. He's in a pretty rough shape himself after going through such lengths to bring you back. He hasn't slept in days, and his options are limited, but seeing as you're awake and available, there might just be a way out of this."

"…?"

"He may be infamous for his strength, but he's weaker than you'd imagine in another sense. He might not make this easy."

"..."

"You might come to find that you two are rather similar."

(If he's taking this long to cut to the chase, then I have a bad feeling about this.)

Kamijou felt the sedative effects of the drug being administered through the IV tempt his weary eyes.

"Look after him, won't you?" adjured the frog-faced doctor as a finishing request.

"…Heh…just who the hell do you take me for…?" he mustered, feeling his consciousness slipping. He wondered why that had even been a question to someone who knew him as well as the frog-faced doctor.

"Thank you. And who knows? You might even find some benefit to it. When you shine a light in a mirror, a light shines back, after all."

Vague impressions of a mirror boy flashed through Kamijou's head, but before he could put two and two together, the sedative effects took hold and Kamijou Touma sank back into unconsciousness.

* * *

**Part 4**

Between dreams and hazy memories, Kamijou Touma reminisced on the life he had lived. It was said that before death, one would witness their entire life flash before their eyes. Kamijou wondered whether or not this was what it was like, and if so, what that might say about what was yet to come.

The memories he'd held before his symbolic death on July 28th were supposedly gone forever, but right now, they felt somewhat closer. Not close enough to be coherent, but it was there. It felt somewhat like déjà vu, or like recalling vague impressions of a past life.

He saw the hazy smiling faces of his parents, black cameras, a flat-chested girl with honey-blonde hair, cracked eggs with a petite girl with short chestnut hair, and finally, white feathers falling from the sky. From there, the memories solidified a bit. The faces and scenes he saw then were more familiar, but he still thought he was missing something.

Kamijou Touma, with his live and let live life philosophy, had never gotten all too hung up on his lost memories aside from the communication difficulties. Nevertheless, he felt as though something important and decisive was buried underneath the hazy impressions of his past life. But when he tried to reach out for them, color drained from his surroundings and he found himself falling into a void. His head spun, so he closed his eyes.

_"You...should stay away from me…"_

His eyes jolted open at the dejected-sounding voice. He saw a white silhouette with the proportions of a young child juxtaposing the darkness. He tried to call out and move, but from then on, his actions weren't his own, and his words weren't either. The more he struggled, the more the memory distorted. By the time Kamijou gave up and opted for listening, he couldn't hear his own voice and could barely hear that of the whiteness.

_"...f-friends?...I hurt the people who get close to me…no one…won't let...close enough...hurt again...no one...try…"_

The whiteness trailed off, but gave a shy smile before fading, and the lingering vestiges of a memory slipped yet again from Kamijou's fingertips as he drifted between dreams.

The feeling of tears on his right hand tugged at the memories within his heart, recalling of one person he failed to save. He recalled his instinctual desire to protect that kid's smile and to destroy everything that may threaten it, and reiterated it.

* * *

Between sparse periods of fevered consciousness, Accelerator skeptically speculated on the impending uncertainty of the future. Heaven Canceller and his subordinates seemed to be handling his predicament rather well, but he wondered how long they could keep it up. Without specifics and thus treatment options, there was only so much they could do until ticking time bomb Accelerator caused possibly irreversible mass destruction. The limitation of not having limitations was truly an undersold limitation.

Causing mass destruction due to not understanding a certain condition or capability, is something Accelerator was no stranger to. Academy City scientists, researchers, and officials were generally depraved bastards that had gaslit their #1 for years. They bred him to see himself as the embodiment of darkness and then groomed him to be the ultimate weapon, property of AC. And he may just be a statistic. The "fucked up or fucked over by Academy City" population was perhaps greater than the esper population itself. Still, Academy City had taught him the specifications of his power and thereby fostered him to control it, which is all the Level 5 could really ask for at the time given the cards he'd been dealt in life and his dwindling hope in his capacity for the light.

But the weakest Level 0 had taken the strongest Level 5's deterministic illusion and broke it with his own fist. More than once, one might add. Every time Accelerator found himself past the point of no return, every time he had believed himself beyond saving, that boy had dragged him back without hesitation and discrimination. He reminded him a lot of someone he knew a long time ago.

_But even he…_

Accelerator had cast those dissociated memories to the void, alongside his birthname. Nevertheless, under his feverish delirium, he didn't have enough strength or coherence to force them back down. And so he merely remembered. He grasped the heartrendingly nostalgic lingering warmth of a certain small right hand that fit perfectly between his.

_"Thank you…I'm sorry…goodbye."_

If Accelerator had enough coherence to associate sentiments and ego to his dissociated memories, he may have deadass unintentionally caused the mass destruction he'd so feared. But he ceded the reins to Heaven Canceller and his plans for his convalescence. Already at the end of his rope, at the very least, he could trust that the frog-faced doctor's plans couldn't be as screwed up as Aleister Crowley's. And having set aside his active role and donned a passive one, he decided not to work himself up over it and to just let someone else handle it. He reiterated his intent to steer clear of any trouble if he could help it.

Doctor's orders.

* * *

Probably should have saved this for the end but I wanted to get it out of the way first.

This was originally going to be the second half of a two-act series with twelve parts each. The first half would represent day and be more active and adventurous. It would focus on Kamijou while being told from Accelerator's perspective as he comes to know the more human sides of the hero everyone so admired. This, the second half, would represent night and be more reflective and dramatic. It, in turn, would focus on Accelerator, be told from Kamijou's perspective, and explore the more human sides of the monster everyone so feared. Because I want to break down these multifaceted characters to their core, OOC is somewhat a given, but I hope it's still within the margin of verisimilitude.

The first was supposed to follow Kamachi's expansive style a bit closer, but in the end I decided that I hadn't brushed up on source material enough to be confident that I could do it justice. Since the second would be more speculative, allow for more creative freedom, and by thematic nature be more my cup of tea, I decided to go ahead and jump into it first. Decision on implementing the first act would be deferred for another time.

"Constructive criticism is welcome and appreciated!" I say, knowing full well that this is my first time posting something online and that I probably won't be able to take it as well as I hope. But for real though, go nuts show nuts with your criticism. Tear me the fuck apart. Start some unnecessary pageant mom-esque discourse on who's the better protagonist or hit me up with those ad hominem attacks. Don't actually, but for real. Why do parts of this fandom feel the need to pit these two against each other on some kind of two-dimensional basis of superiority, thereby detracting from both their four-dimensional individual characters and the parallels Kamachi establishes?

All that said, I hope you enjoy this self-indulgent clusterfuck of words.

Thanks for reading!

Also, indefinite hiatus while I work on trying to do these characters justice.


End file.
